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Current Research and Scholarly Interests

Dr. Park's research interests are in the diagnosis and management of pancreatic cysts, acute and chronic pancreatitis. His approach incorporates methods in health services research including the use of observational datasets, cost-effectiveness studies, and the development of clinical cohorts.

Clinical Trials

Feasibility of a Mobile Electronic Mindfulness Therapy Service for Chronic PancreatitisNot Recruiting

The research objective of this pilot study is to test the feasibility of a mobile electronic
mindfulness therapy service for patients with definite or suspected chronic pancreatitis.
A secondary aim will be to determine the effect of the intervention on a symptom
severity/global assessment of improvement for patients with chronic pancreatitis. The
investigators hypothesize that a one-month period of daily mindfulness therapy delivered via
a phone messaging service will reduce symptoms.

Abstract

The aim of this study was to compare the American Gastroenterological Association guidelines (AGA criteria), the 2012 (Fukuoka criteria), and 2006 (Sendai criteria) International Consensus Guidelines for the diagnosis of advanced pancreatic cystic neoplasms.All patients who underwent surgical resection of a pancreatic cyst from August 2007 through January 2016 were retrospectively analyzed at a single tertiary academic center. Relevant clinical and imaging variables along with pathology results were collected to determine appropriate classification for each guideline. Advanced pancreatic cystic neoplasms were defined by the presence of either high-grade dysplasia or cystic adenocarcinoma. Diagnostic accuracy was measured by ROC analysis.A total of 209 patients were included. Both the AGA and Fukuoka criteria had a higher diagnostic accuracy for advanced neoplastic cysts than the Sendai criteria: AGA ROC 0.76 (95% CI 0.69-0.81), Fukuoka ROC 0.78 (95% CI 0.74-0.82), and Sendai ROC 0.65 (95% CI 0.61-0.69) (p

Abstract

Patients with chronic pancreatitis (CP) have substantially impaired quality of life (QOL) both physically and mentally. Mindfulness therapy is a form of treatment that has been shown to be beneficial in many medical conditions but has not been evaluated in the CP patient population.The aims of this study were (1) to test the feasibility and usability of a novel telephone-based mindfulness therapy service for patients with CP and (2) to determine whether there was any effect on CP quality of life.We recruited ten patients with suspected or confirmed CP and five controls who were asked to utilize our telephone-based mindfulness therapy service daily for 28 days. Feasibility of the service was defined as the fraction of subjects with a ≥50% compliance rate. Usability was assessed using a System Usability Scale (SUS). QOL was evaluated using the SF-36 questionnaire and the Pancreatitis Quality of Life Instrument (PANQOLI). Paired t tests were used to compare the SF-36 and PANQOLI pre- and post-intervention.There was an overall compliance rate of 67%. The mean SUS score for all participants was 79.3, above the average published score of 68. Results showed a significant improvement in the SF-36 Mental Component Summary scores after 28 days of mindfulness therapy for patients with CP, t(9) = 2.48, p = 0.035. There was also a significant improvement in the mean total PANQOLI scores in CP patients, t(9) = 2.41, p = 0.04, most notably in the social domain.Our telephone-based mindfulness therapy service represents a feasible and easily usable treatment adjunct for patients with CP, which may provide benefit in QOL by improving mental health-related domains.

Abstract

We have established a multicenter international consortium to better understand the natural history of acute pancreatitis (AP) worldwide and to develop a platform for future randomized clinical trials.The AP patient registry to examine novel therapies in clinical experience (APPRENTICE) was formed in July 2014. Detailed web-based questionnaires were then developed to prospectively capture information on demographics, etiology, pancreatitis history, comorbidities, risk factors, severity biomarkers, severity indices, health-care utilization, management strategies, and outcomes of AP patients.Between November 2015 and September 2016, a total of 20 sites (8 in the United States, 5 in Europe, 3 in South America, 2 in Mexico and 2 in India) prospectively enrolled 509 AP patients. All data were entered into the REDCap (Research Electronic Data Capture) database by participating centers and systematically reviewed by the coordinating site (University of Pittsburgh). The approaches and methodology are described in detail, along with an interim report on the demographic results.APPRENTICE, an international collaboration of tertiary AP centers throughout the world, has demonstrated the feasibility of building a large, prospective, multicenter patient registry to study AP. Analysis of the collected data may provide a greater understanding of AP and APPRENTICE will serve as a future platform for randomized clinical trials.

Abstract

A workshop was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases to address the research gaps and opportunities in pancreatic EUS. The event occurred on July 26, 2017 in 4 sessions: (1) benign pancreatic diseases, (2) high-risk pancreatic diseases, (3) diagnostic and therapeutics, and (4) new technologies. The current state of knowledge was reviewed, with identification of numerous gaps in knowledge and research needs. Common themes included the need for large multicenter consortia of various pancreatic diseases to facilitate meaningful research of these entities; to standardize EUS features of different pancreatic disorders, the technique of sampling pancreatic lesions, and the performance of various therapeutic EUS procedures; and to identify high-risk disease early at the cellular level before macroscopic disease develops. The need for specialized tools and accessories to enable the safe and effective performance of therapeutic EUS procedures also was discussed.

How to Be an Advocate for Your Profession and Your Practice.Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological AssociationPark, W. G.2017; 15 (10): 1489–91

Abstract

Cigarette smoke has been identified as an independent risk factor for chronic pancreatitis (CP). Little is known about the mechanisms by which smoking promotes development of CP. We assessed the effects of aryl hydrocarbon receptor (AhR) ligands found in cigarette smoke on immune cell activation in humans and pancreatic fibrosis in animal models of CP.We obtained serum samples from patients with CP treated at Stanford University hospital and healthy individuals (controls) and isolated CD4(+) T cells. Levels of interleukin-22 (IL22) were measured by enzyme-linked immunosorbent assay and smoking histories were collected. T cells from healthy nonsmokers and smokers were stimulated and incubated with AhR agonists (2,3,7,8-tetrachlorodibenzo-p-dioxin or benzo[a]pyrene) or antagonists and analyzed by flow cytometry. Mice were given intraperitoneal injections of caerulein or saline, with or without lipopolysaccharide, to induce CP. Some mice were given intraperitoneal injections of AhR agonists at the start of caerulein injection, with or without an antibody against IL22 (anti-IL22) starting 2 weeks after the first caerulein injection, or recombinant mouse IL22 or vehicle (control) intraperitoneally 4 weeks after the first caerulein injection. Mice were exposed to normal air or cigarette smoke for 6 h/d for 7 weeks and expression of AhR gene targets was measured. Pancreata were collected from all mice and analyzed by histology and quantitative reverse transcription polymerase chain reaction. Pancreatic stellate cells and T cells were isolated and studied using immunoblot, immunofluorescence, flow cytometry, and enzyme-linked immunosorbent analyses.Mice given AhR agonists developed more severe pancreatic fibrosis (based on decreased pancreas size, histology, and increased expression of fibrosis-associated genes) than mice not given agonists after caerulein injection. In mice given saline instead of caerulein, AhR ligands did not induce fibrosis. Pancreatic T cells from mice given AhR agonists and caerulein were activated and expressed IL22, but not IL17 or interferon gamma. Human T cells exposed to AhR agonists up-regulated expression of IL22. In mice given anti-IL22, pancreatic fibrosis did not progress, whereas mice given recombinant IL22 had a smaller pancreas and increased fibrosis. Pancreatic stellate cells isolated from mouse and human pancreata expressed the IL22 receptor IL22RA1. Incubation of the pancreatic stellate cells with IL22 induced their expression of the extracellular matrix genes fibronectin 1 and collagen type I α1 chain, but not α2 smooth muscle actin or transforming growth factor-β. Serum samples from smokers had significantly higher levels of IL22 than those from nonsmokers.AhR ligands found in cigarette smoke increase the severity of pancreatic fibrosis in mouse models of pancreatitis via up-regulation of IL22. This pathway might be targeted for treatment of CP and serve as a biomarker of disease.

Abstract

Although most pancreatic neuroendocrine tumors are solid, approximately 10% are cystic. Some studies have suggested that cystic pancreatic neuroendocrine tumors are associated with a more favorable prognosis.A retrospective review of all patients with pancreatic neuroendocrine tumors who underwent operative resection between 1999 and 2014 at a single academic medical center was performed. Based on cross-sectional imaging performed before operation, pancreatic neuroendocrine tumors were classified according to the size of the cystic component relative to the total tumor size: purely cystic (100%), mostly cystic (≥50%), mostly solid (<50%), and purely solid (0%). Clinicopathologic characteristics and recurrence-free survival were assessed between groups.In the study, 214 patients met inclusion criteria: 8 with purely cystic tumors, 7 with mostly cystic tumors, 15 with mostly solid tumors, and 184 with purely solid tumors. The groups differed in terms of tumor size (1.5 ± 0.5, 3.0 ± 1.7, 3.7 ± 2.6, and 4.0 ± 3.5 cm), lymph node positivity (0%, 0%, 26.7%, and 34.2%), intermediate or high grade (0%, 16.7%, 20.0%, and 31.0%), synchronous liver metastases (0%, 14.3%, 20.0%, and 26.6%) and need for pancreaticoduodenectomy (0%, 0%, 6.7%, and 25.0%), respectively. No cases of purely cystic pancreatic neuroendocrine tumors were associated with synchronous liver or lymph node metastasis, intermediate/high grade, recurrence, or death due to disease. Among patients presenting without metastatic disease, 10-year recurrence-free survival was 100% in patients with purely and mostly cystic tumors versus 53.0% in patients with purely and mostly solid tumors; however, this difference did not reach statistical significance.Pancreatic neuroendocrine tumors demonstrate a spectrum of biologic behavior with an increasing cystic component being associated with more favorable clinicopathologic features and prognosis. Purely cystic pancreatic neuroendocrine tumors may represent 1 subset that can be safely observed without immediate resection.

Abstract

Chronic pancreatitis is a significant medical problem that impacts a large number of patients worldwide. In 2014, we developed a disease-specific instrument for the evaluation of quality of life in this group of patients: pancreatitis quality of life instrument (PANQOLI). The goal of this study was to evaluate its psychometric properties: its reliability and its construct validity.This is a cross-sectional multi-center study that involved 12 pancreatic disease centers. Patients who met the inclusion/exclusion criteria for chronic pancreatitis were invited to participate. Those who accepted were asked to complete seven questionnaires/instruments. Only patients who completed the PANQOLI were included in the study. Its reliability and its construct validity were tested.A total of 159 patients completed the PANQOLI and were included in the study. They had a mean age of 49.03, 49% were male, and 84% were Caucasian. Six of the 24 items on the scale were removed because of lack of inter-item correlation, redundancy, or lack of correlation to quality of life issues. The final 18-item scale had excellent reliability (Cronbach's alpha coefficient: 0.914) and excellent construct validity with good correlation to generic quality of life instruments (SF-12 and EORTC QLQ-C30/QLQ-PAN26) and lack of correlation to non-quality of life instruments (MAST and DAST). Through exploratory factor analysis, the PANQOLI was found to consist of four subscales: emotional function scale, role function scale, physical function scale, and "self-worth" scale.PANQOLI is the first disease-specific instrument to be developed and validated for the evaluation of quality of life in chronic pancreatitis patients. It has a unique subscale for "self-worth" that differentiates it from other generic instruments. Studies are currently under way to evaluate its use in other populations not included in this study.

Abstract

Chronic pancreatitis is a significant medical problem that impacts a large number of patients worldwide. In 2014, we developed a disease-specific instrument for the evaluation of quality of life in this group of patients: pancreatitis quality of life instrument (PANQOLI). The goal of this study was to evaluate its psychometric properties: its reliability and its construct validity.This is a cross-sectional multi-center study that involved 12 pancreatic disease centers. Patients who met the inclusion/exclusion criteria for chronic pancreatitis were invited to participate. Those who accepted were asked to complete seven questionnaires/instruments. Only patients who completed the PANQOLI were included in the study. Its reliability and its construct validity were tested.A total of 159 patients completed the PANQOLI and were included in the study. They had a mean age of 49.03, 49% were male, and 84% were Caucasian. Six of the 24 items on the scale were removed because of lack of inter-item correlation, redundancy, or lack of correlation to quality of life issues. The final 18-item scale had excellent reliability (Cronbach's alpha coefficient: 0.914) and excellent construct validity with good correlation to generic quality of life instruments (SF-12 and EORTC QLQ-C30/QLQ-PAN26) and lack of correlation to non-quality of life instruments (MAST and DAST). Through exploratory factor analysis, the PANQOLI was found to consist of four subscales: emotional function scale, role function scale, physical function scale, and "self-worth" scale.PANQOLI is the first disease-specific instrument to be developed and validated for the evaluation of quality of life in chronic pancreatitis patients. It has a unique subscale for "self-worth" that differentiates it from other generic instruments. Studies are currently under way to evaluate its use in other populations not included in this study.

Abstract

The management of acute pancreatitis (AP) has evolved through enhanced understanding of the disease. Despite several evidence-based practice guidelines for AP, our hypothesis is that many hospitals still use historical treatments rather than adhere to the current guidelines, which have demonstrated shorter hospital stays, decreased infectious complications, decreased morbidity, and decreased mortality.Seventy-eight patients transferred to our institution with AP from 2010-2014 were retrospectively studied to compare pretransfer versus posttransfer adherence to current practice guidelines. Primary measures included use of antibiotics (abx), enteral nutrition, drainage of asymptomatic pseudocysts, and interventions for necrosis in the early phase (<4 wk).Pretransfer, abx were given to 51 patients; however, posttransfer, abx were discontinued in 33 patients and started in 6 patients within 24 h of admission (pretransfer versus posttransfer abx, 51 versus 24, P 4 wk from initial episode of AP. Pretransfer, five patients had pancreatic debridement in the early phase, which resulted in prolonged postoperative length of stay compared with eight patients requiring debridement, which were delayed (early versus late, 56 versus 16 d, P

Abstract

Better diagnostic tools are needed to differentiate pancreatic cyst subtypes. A previous metabolomic study showed cyst fluid glucose as a potential marker to differentiate mucinous from non-mucinous pancreatic cysts. This study seeks to validate these earlier findings using a standard laboratory glucose assay, a glucometer, and a glucose reagent strip.Using an IRB-approved prospectively collected bio-repository, 65 pancreatic cyst fluid samples (42 mucinous and 23 non-mucinous) with histological correlation were analyzed.Median laboratory glucose, glucometer glucose, and percent reagent strip positive were lower in mucinous vs. non-mucinous cysts (P<0.0001 for all comparisons). Laboratory glucose<50 mg/dl had a sensitivity of 95% and a specificity of 57% (LR+ 2.19, LR- 0.08). Glucometer glucose<50 mg/dl had a sensitivity of 88% and a specificity of 78% (LR+ 4.05, LR- 0.15). Reagent strip glucose had a sensitivity of 81% and a specificity of 74% (LR+ 3.10, LR- 0.26). CEA had a sensitivity of 77% and a specificity of 83% (LR+ 4.67, LR- 0.27). The combination of having either a glucometer glucose<50 mg/dl or a CEA level>192 had a sensitivity of 100% but a low specificity of 33% (LR+ 1.50, LR- 0.00).Glucose, whether measured by a laboratory assay, a glucometer, or a reagent strip, is significantly lower in mucinous cysts compared with non-mucinous pancreatic cysts.

Abstract

Without a reliable biopsy technique for pancreatic cysts, consensus-based guidelines are used to guide surgical utilization. The primary objective of this study was to characterize the proportion of operations performed outside of these guidelines.A 5-year retrospective review between July 1, 2007, and June 30, 2012, was performed of consecutive patients seen at a single tertiary medical center for a pancreatic cyst. Manual chart review for relevant clinical variables and cyst characteristics was performed.During this period, 148 patients underwent surgery, and of these, 23 (16 %) patients had no high-risk criteria by the 2006 Sendai criteria. None of these harbored high-grade dysplastic or cancerous lesions. A high cyst carcinoembryonic antigen (CEA) level (35 %), patient anxiety (26 %), and physician concern (22 %) were explicit reasons to proceed to surgery. An elevated cyst CEA level >192 ng/ml was the most significant predictor (OR 5.14 (95 % confidence interval (CI) 1.47-18.0) for surgery without high-risk criteria.A high cyst CEA level was significantly associated with the decision to operate outside of consensus-based guidelines. The misuse of cyst CEA in the management of pancreatic cysts negatively impacts patient anxiety, increases physician uncertainty, and leads to surgery with minimal benefit.

Abstract

To evaluate the new RetroView™ colonoscope and compare its ability to detect simulated polyps "hidden" behind colonic folds with that of a conventional colonoscope, utilizing anatomic colon models.Three anatomic colon models were prepared, with twelve simulated polyps "hidden" behind haustral folds and five placed in easily viewed locations in each model. Five blinded endoscopists examined two colon models in random order with the conventional or RetroView™ colonoscope, utilizing standard withdrawal technique. The third colon model was then examined with the RetroView™ colonoscope withdrawn initially in retroflexion and then in standard withdrawal. Polyp detection rates during standard and retroflexed withdrawal of the conventional and RetroView™ colonoscopes were determined. Polyp detection rates for combined standard and retroflexed withdrawal (combination withdrawal) with the RetroView™ colonoscope were also determined.For hidden polyps, retroflexed withdrawal using the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (85% vs 12%, P = 0.0001). For hidden polyps, combination withdrawal with the RetroView™ colonoscope detected more polyps than the conventional colonoscope in standard withdrawal (93% vs 12%, P ≤ 0.0001). The RetroView™ colonoscope in "combination withdrawal" was superior to other methods in detecting all (hidden + easily visible) polyps, with successful detection of 80 of 85 polyps (94%) compared to 28 (32%) polyps detected by the conventional colonoscope in standard withdrawal (P < 0.0001) and 67 (79%) polyps detected by the RetroView™ colonoscope in retroflexed withdrawal alone (P < 0.01). Continuous withdrawal of the colonoscope through the colon model while retroflexed was achieved by all endoscopists. In a post-test survey, four out of five colonoscopists reported that manipulation of the colonoscope was easy or very easy.In simulated testing, the RetroView™ colonoscope increased detection of hidden polyps. Combining standard withdrawal with retroflexed withdrawal may become the new paradigm for "complete screening colonoscopy".

Abstract

There is significant research interest in developing and validating novel pancreatic cyst-fluid biomarkers given the increasing recognition of the prevalence of pancreatic cysts and their associated malignant potential. Although current international consensus guidelines are helpful, they fail to diagnose with certainty the cyst type and the level of epithelial dysplasia. They also fall short in predicting the future likelihood of malignant transformation. A systematic review was performed with the objective of summarizing cyst-fluid-based biomarkers that have been published in the medical literature over the past 10 years and characterizing the current quality of evidence. Our review demonstrates that there is an increasing interest in this topic with several different and innovative approaches including DNA, RNA, proteomic, and metabolomics profiling. Further techniques to improve upon cytological yield have also been studied. Besides identifying potentially useful clinical biomarkers, these empiric approaches have provided further insight into their pathogenesis. The level of evidence for the vast majority of these studies, however, is limited to retrospective early validation studies. The path forward will be to select out the most promising biomarkers and develop multicenter consortiums capable of capturing adequate sample sizes with appropriate study designs.

Abstract

The study aimed to better define the epidemiology of idiopathic acute pancreatitis (IAP).We identified admissions with primary diagnosis of acute pancreatitis (AP) in Nationwide Inpatient Sample between 1998 and 2007. Idiopathic AP was defined as all cases after excluding International Classification of Diseases, Ninth Revision, codes for other causes of AP (including biliary, alcoholic, trauma, iatrogenic, hyperparathyroidism, hyperlipidemia, etc).Among the primary admissions for AP, 26.9% had biliary pancreatitis, 25.1% alcoholic, and 36.5% idiopathic. Idiopathic AP had estimated 81,8025 admissions with a mean hospitalization of 5.6 days. Patients with IAP accounted for almost half of the fatalities among the cases of AP (48.2%) and had a higher mortality rate than both patients with biliary pancreatitis and patients with alcoholic pancreatitis (1.9%, 1.5%, and 1.0%, respectively, P < 0.01). Forty-six percent of patients with biliary pancreatitis underwent cholecystectomy during the index hospitalization, compared with 0.42% of patients with IAP. Patients with IAP had a demographic distribution similar to that of patients with biliary AP (female predominant and older), which was distinct from patients with alcoholic pancreatitis (male predominant and younger). There was a gradual but steady decrease in the incidence of IAP, from 41% in 1998 to 30% in 2007.Despite improving diagnostics, IAP remains a common clinical problem with a significant mortality. Standardization of the clinical management of these patients warrants further investigation.

Abstract

Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of radiographic calcifications in these tumors remains unclear.From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival.Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3 cm, P=0.04) and more commonly associated with lymph node metastasis (75 vs. 35%, P=0.01), synchronous liver metastasis (62 vs. 21%, P<0.01), and intermediate tumor grade (80 vs. 31%, P<0.01). On multivariate analysis of factors available preoperatively, calcifications (P=0.01) and size (P<0.01) remained independent predictors of lymph node metastasis. Overall survival after resection was significantly worse in the presence of synchronous liver metastasis (5-year, 64 vs. 86%, P=0.04), but not in the presence of radiographic calcifications.Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.

Abstract

Hyaluronic acid (HA) provides a long-lasting and distinct mucosal elevation for EMR, but expense and inconvenience have limited its adoption.To evaluate the safety and efficacy of an over-the-counter 0.15% HA preparation for EMR.Retrospective study.Veterans Administration Hospital and university hospital.30 patients with a total of 32 colonic lesions and 1 duodenal lesion.EMR by using HA.En bloc resection rate and complications.EMR was successful in all cases. En bloc resection was achieved in 26 of the 28 lesions up to 25 mm in diameter. Two lesions, both with fibrosis from prior attempted resection, had trace residual tissue necessitating cauterization with argon plasma. Five lesions measuring 30 mm to 60 mm all required piecemeal resection. There was one complication, a postpolypectomy bleed.Small number of patients and retrospective design.EMR may be performed safely and effectively by using an inexpensive, over-the-counter 0.15% HA preparation. Further studies are needed to verify the results of this study and to compare the safety and efficacy of this HA preparation with saline solution.

Abstract

Pancreatic cysts are increasingly recognized as a dilemma in clinical practice because of their uncertain risk of malignancy. Because diagnosis by cytology is insensitive, current guidelines suggest using radiographic and clinical criteria to determine the appropriateness of surgery or surveillance, although this is far from perfect. Several cyst fluid biomarkers have been reported to aid diagnosis, and to date, carcinoembryonic antigen is the most accurate in detecting potentially cancerous mucinous cysts, but not in detecting malignant cysts. Recent studies have highlighted novel cyst fluid biomarkers based on DNA analysis, protein expression profiling, and secreted proteins that, if validated, may improve diagnosis and management.

Abstract

Image-guided radiation therapy (IGRT) accurately delivers a high dose of potentially tumoricidal radiation to its target while sparing adjacent healthy tissue. Application of IGRT to unresectable pancreatic cancer requires the use of fiducials to track the precise location of the tumor. Fiducial markers have been successfully placed endoscopically.To determine the feasibility of EUS-guided gold fiducial placement for IGRT.Prospective case series.Tertiary medical center.Consecutively referred patients with locally advanced unresectable pancreatic adenocarcinoma for EUS-guided insertion of gold fiducials from December 2006 to February 2009.Under only EUS guidance, fiducial markers were deployed into or near the tumor by using a 19-gauge needle. In most cases, a sterile water injection technique was used to insert the fiducials. Fluoroscopy was not used in any case.Successful placement of an adequate number of fiducials to proceed with IGRT as determined by CT.Fifty-seven consecutive patients were included. Fifty cases (88%) were successful. Of the cases in which fiducial placement was attempted and follow-up was adequate, 94% (50 of 53) of cases were successful.Single-center, nonrandomized study.EUS-guided fine-needle insertion was safe and effective in delivering gold fiducial markers for image-guided radiation therapy. Fluoroscopy was not required for successful fiducial placement.

Abstract

Colorectal cancer is the second leading cause of cancer death in the United States. Prevention has focused on the detection and removal of polypoid neoplasms. Data are limited on the significance of nonpolypoid colorectal neoplasms (NP-CRNs).To determine the prevalence of NP-CRNs in a veterans hospital population and to characterize their association with colorectal cancer.Cross-sectional study at a veterans hospital in California with 1819 patients undergoing elective colonoscopy from July 2003 to June 2004.Endoscopic appearance, location, size, histology, and depth of invasion of neoplasms.The overall prevalence of NP-CRNs was 9.35% (95% confidence interval [95% CI], 8.05%-10.78%; n = 170). The prevalence of NP-CRNs in the subpopulations for screening, surveillance, and symptoms was 5.84% (95% CI, 4.13%-8.00%; n = 36), 15.44% (95% CI, 12.76%-18.44%; n = 101), and 6.01% (95% CI, 4.17%-8.34%; n = 33), respectively. The overall prevalence of NP-CRNs with in situ or submucosal invasive carcinoma was 0.82% (95% CI, 0.46%-1.36%; n = 15); in the screening population, the prevalence was 0.32% (95% CI, 0.04%-1.17%; n = 2). Overall, NP-CRNs were more likely to contain carcinoma (odds ratio, 9.78; 95% CI, 3.93-24.4) than polypoid lesions, irrespective of the size. The positive size-adjusted association of NP-CRNs with in situ or submucosal invasive carcinoma was also observed in subpopulations for screening (odds ratio, 2.01; 95% CI, 0.27-15.3) and surveillance (odds ratio, 63.7; 95% CI, 9.41-431). The depressed type had the highest risk (33%). Nonpolypoid colorectal neoplasms containing carcinoma were smaller in diameter as compared with the polypoid ones (mean [SD] diameter, 15.9 [10.2] mm vs 19.2 [9.6] mm, respectively). The procedure times did not change appreciably as compared with historical controls.In this group of veteran patients, NP-CRNs were relatively common lesions diagnosed during routine colonoscopy and had a greater association with carcinoma compared with polypoid neoplasms, irrespective of size.

Abstract

The diagnosis of chronic hepatitis B virus (HBV) infection is made using a combination of serological, virologic, biochemical, and histologic markers. The natural history of HBV infection can be divided into four phases: immune tolerance, immune clearance (HBeAg-positive chronic hepatitis B), inactive HBsAg carrier, and reactivation (HBeAg-negative chronic hepatitis B). Patients in the immune clearance and reactivation phases, with elevated alanine aminotransferase (ALT) and HBV DNA levels, are candidates for antiviral therapy. The primary goal of therapy for chronic hepatitis B is suppression of viral replication, which has been shown to reduce hepatic necroinflammation and retard progression of hepatic fibrosis. Long-term suppression of serum HBV DNA is likely to reduce progression to cirrhosis and hepatic decompensation and decrease the risk of hepatocellular carcinoma. Current antiviral therapy for chronic hepatitis B includes interferon alfa, peginterferon alfa-2a, lamivudine, adefovir, entecavir, and telbivudine. In patients with HBeAg-positive chronic hepatitis B, antiviral treatment is indicated when the serum HBV DNA level is = or > 10(5) copies/mL (20,000 IU/mL) and the ALT level is elevated. For HBeAg-negative patients, the threshold for initiation of therapy is lower, i.e., a serum HBV DNA level = or > 10(4) copies/mL (2,000 IU/mL) in association with an elevated ALT level. The presence of at least moderate necroinflammation and the presence of fibrosis on liver biopsy, which is optional and not mandatory before therapy, may be useful in supporting the decision to initiate therapy, particularly in patients with normal ALT levels. While undergoing therapy, patients require monitoring every 3 to 6 months to ensure compliance and to test for the development of resistance if an oral agent is used. Issues that remain controversial or need to be studied further are the necessity of a baseline liver biopsy, the HBV DNA and ALT thresholds for initiation of therapy, the optimal duration of antiviral therapy, selection of one agent over another, and the role of combination therapy.

Abstract

The diagnosis of chronic hepatitis B virus (HBV) infection is made using a combination of serological, virological, biochemical, and histological markers. The natural history of HBV infection can be divided into 3 phases: immune tolerant, immune active with chronic hepatitis B, and inactive carrier; patients in the immune active phase are candidates for antiviral therapy. The primary goal of therapy for chronic hepatitis B is suppression of viral replication, which has been shown to reduce hepatic necroinflammation and retard progression of hepatic fibrosis. Long-term suppression of serum HBV DNA is likely to reduce progression to cirrhosis and hepatic decompensation and may also decrease the risk of hepatocellular carcinoma. Current antiviral therapy for chronic hepatitis B includes interferon alpha, lamivudine and adefovir, with recent studies demonstrating good safety and efficacy of peginterferon and other nucleoside analogues that will soon become additional treatment options. In patients with HBeAg-positive chronic hepatitis B, antiviral treatment is indicated when the serum HBV DNA level is = or >10(5) copies/mL and the alanine aminotransferase (ALT) level is elevated, particularly greater than 2 times the upper limits of normal. For HBeAg-negative patients, the threshold for initiation of therapy is a HBV DNA level = or >10(4) in association with an elevated ALT level. The presence of at least moderate necroinflammation and the presence of fibrosis on liver biopsy, which is optional and not mandatory before therapy, may be useful in supporting the decision to initiate therapy. While undergoing therapy, patients require monitoring every 3 to 6 months to ensure compliance and to test for the development of resistance if an oral agent is used. Issues that remain controversial or need to be studied further are the necessity of a baseline liver biopsy, the HBV DNA and ALT thresholds for initiation of therapy, the optimal duration of antiviral therapy, selection of one agent over another, and the role of combination therapy.